RESPONSIBLE USE OF ANTIMICROBIALS IN FISH PRODUCTION

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2 RESPONSIBLE USE OF ANTIMICROBIALS IN FISH PRODUCTION Fish farmers have a responsibility to safeguard the health of the fish on their farm. Where appropriate farmers may ask their veterinary surgeon to help them discharge this responsibility. Farmers and fish keepers can play a major role in ensuring the responsible use of medicines on fish farms.

3 SUBSTANCES DANGEROUS FOR THE HUMAN HEALTH Malachite Green Formaldehyde In Europe and the United States its use is strictly prohibited in farmed fish for human consumption. Residues of malachite green and its metabolite leucomalachite remain permanently in the tissues (which may take the characteristic greenish). Studies in rats and mouse show carcinogenic and mutagenic effectswith the formation of lung adenomas, thyroid cancer, liver and mammary gland. S.J. Culp et al. (2002). Mutagenicity and carcinogenicity in relation to DNA adduct formation in rats fed leucomalachite green. (2005). Toxicology and Carcinogenesis Studies of Malachite Green Chloride and Leucomalachite Green (CAS Nos and The carcinogenicity has been found in rodents, where formaldehyde causes an incidence rate of cancer of the nose and throat much higher than normal. Formaldehyde is able to interfere with the links betweendna and proteins. The International Agency for Research on Cancer (IARC) since 2004has included formaldehyde in the list of substances considered for certain carcinogenic for humans. Must be carefully valued the risks to workers at industrial processes that use formaldehyde. In 2006, the American agency of Neurology showed that formaldehyde can cause sclerosis in humans

4 The types of chemicals and veterinary drugs used in aquaculture include CHEMOTHERAPEUTANTS, PESTICIDES, OXIDANTS, DISINFECTANTS, ALGICIDES, HERBICIDES and BIOCIDES in general

5 Legal issue It is the responsibility of those using, prescribing, and/or recommending the use of regulated Products to know which products can be legally used and with what restrictions under local regulations. Remember, regulated product uses may vary by location, Species, life stage, and culture conditions or methods. The chemical products are often registered as disinfectans and sanitizers, then those can be used on all structures (tanks, walls, etc) and tools (nets, boots, etc) Check if the current legislation allow for the direct use over the fish of every product that we will discuss.

6 CHEMOTHERAPEUTANTS for aquaculture in Europe APPROVED SPECIFICALLY PROHIB Amoxicillin, Florfenicol, Flumequine, Oxolinic Acid, Oxytetracycline, Sarafloxacin Sulfadiazinetrimethoprim. Chloramphenicol, Nitrofurans

7 In Carp-farming bacterial diseases of fish can be successfully treated with medicated feeds APPROVED Amoxicillin, Florfenicol, Flumequine, Oxolinic Acid, Oxytetracycline, Sarafloxacin Sulfadiazinetrimethopr im. Carp erythrodermatitis; ulcer disease Aeromonas salmonicida Columnaris disease Flexibacter columnaris Bacterial gill disease Flavobacterium branciophyla

8 Examples of possible dosage rates for some common antibiotics or drugs 1. The feed is then administered for a recommended treatment period, according to the specific disease to be treated and the instructions of a veterinary practitioner. 2. Important that treated fish must not be harvested for food use until a specified withdrawal period has elapsed 3. Medicated feed needs to be kept under adequate storage conditions, such as in a cool dry place kept separate from other feeds, to avoid any deterioration of the feed quality and drug efficacy

9 The use of the Biocides The administration of biocides and disinfectants in the water directly is the most common method for therapy in fish health. We must keep in mind that the chemical and physical components of the water, greatly modify the effectiveness of the molecules used, in particular: Temperature Hard water Salinity PH

10 The use of the Biocides Dips (medicinal baths) a) Dip in continuous b) Short dip c) Permanent dip

11 Dip in continuous This method is used when you can not stop the flow (rivers or streams). The product should be placed in a container with valve on top of the channel. Important to calculate well the water flow. The product must come to the end of the canal in up to 40 minutes

12 Short dip The treatment must be done simultaneously on all channels. Spread evenly over the surface. You can do a little refill on top of the channel, if necessary.

13 Permanent dip If you treat a large basin with regular changes less than 2-3 per day, pay attention to dosages. Normally the lower doses, will remove only the free forms of the parasites and young. Hardly the treatment can solve a serious infestation.

14 BIOCIDES making an example Mix of hydrogen peroxide (H2O2) and peracetic acid (CH3COOOH). kill viruses, bacteria gram+ and gram-, mold, yeast, micelia and most of the parasites. Gill bacteria disease Saprolegnia (Saprolegnia spp.) Ictio (Ichthyophthirius multifiliis) Tricodina (Trichodina spp. Trichodinella spp.) Ciliates (Epistylis spp. Apiosoma spp.) Costia (Icthyobodo necator) Chilodonella (Chilodonella piscicola)

15 BIOCIDES making an example Dosage Mix of hydrogen peroxide (H2O2) and peracetic acid (CH3COOOH). All these organism and generally for all the eggs and free stages of the life circle of many other parasites may be removed by: 1. Dip in continuos for 40 minutes with dosage ppm. 2. In a short dip use ppm. 3. In permanent dip the correct range is ppm. Repeat the treatment for a few days.

16 BIOCIDES making an example Mix of hydrogen peroxide (H2O2) and peracetic acid (CH3COOOH). Girodattilo (Gyrodactylus spp.) Dattilogiro (Dactylogyrus spp.) In these cases is very difficult to remove with bath during the day because these parasites are hooked. But during the night shift and try a body part undamaged better vascularized. Can be removed with a nigth-time treatment.

17 BIOCIDES making an example Mix of hydrogen peroxide (H2O2) and peracetic acid (CH3COOOH). Precautions and tips First treatment half dosage. Always use rubber gloves and goggles. After 40 minutes the product is strongly inactivated (more than80%) so check if the treatment is in a channel if the product arrive at the end in 40 minutes. Keep in the shade and away from heat sources.

18 All live microorganisms, are subject to the phenomenon called chemoresistance. Microorganisms change over time, some of their characteristics to become resistant to disinfectants they come in contact. For this reason it is necessary to alternate the active ingredients.

19 management of viral disease Spring vireamia of carp (SVC). Its pathogen is the Rhabdoviris carpio (RNS virus). Koi herpes virus (KHV). It is caused by a DNA virus, which was first described in VACCINATION HAS A MAJOR PROPHYLACTIC ROLE IN PROTECTION OF FISH IN CARP CULTURE VACCINATION AGAINST VIRAL DISEASES IS EXPENSIVE THE EFFICIENT MEASURE FOR KEEPING FISH HEALTHY IS THROUGH PREVENTION which includes: the maintenance of a proper rearing environment, ensuring adequate feeding and fish friendly handling.

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